Expand this Topic clickable element to expand a topic
Skip to content
Optica Publishing Group
Journal Home About Issues in Progress Current Issue All Issues Feature Issues

Bilayer Al wire-grids as broadband and high-performance polarizers

Yasin Ekinci, Harun H. Solak, Christian David, and Hans Sigg

Open Access Open Access

Abstract

We have fabricated, characterized and theoretically analyzed the performance of bilayer (or stacked) metallic wire-grids. The samples with 100 nm period were fabricated with extreme-ultraviolet interference lithography. Transmission efficiency over 50% and extinction ratios higher than 40 dB were measured in the visible range with these devices. Simulations using a finite-difference time-domain algorithm are in agreement with the experimental results and show that the transmission spectra are governed by Fabry-Perot interference and near-field coupling between the two layers of the structure. The simple fabrication method involves only a single lithographic step without any etching and guarantees precise alignment and separation of the two wire-grids with respect to each other.

©2006 Optical Society of America

Full Article  |  PDF Article
More Like This
Al wire-grid polarizer using the s-polarization resonance effect at the 0.8-µm-wavelength band

Hitoshi Tamada, Tohru Doumuki, Takashi Yamaguchi, and Shuichi Matsumoto
Opt. Lett. 22(6) 419-421 (1997)

Broadband nanowire-grid polarizers in ultraviolet-visible-near-infrared regions

Z.Y. Yang and Y.F. Lu
Opt. Express 15(15) 9510-9519 (2007)

Fabrication and characterization of a deep ultraviolet wire grid polarizer with a chromium-oxide subwavelength grating

Kosuke Asano, Satoshi Yokoyama, Atsushi Kemmochi, and Toyohiko Yatagai
Appl. Opt. 53(13) 2942-2948 (2014)

View More...

Cited By

Optica participates in Crossref's Cited-By Linking service. Citing articles from Optica Publishing Group journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (7)
Fig. 1.
Fig. 1. Schematic diagram of a bilayer wire-grid with period p, photoresist height h, photoresist width a, and metal thickness t. Separation between the layers is defined by the thickness of the metal and photoresist layers, d = h-t. Photoresist duty cycle is f = a/p.

Download Full Size | PDF

Fig. 2.
Fig. 2. Cross-sectional (a) and top-down (b) scanning electron microscope images of a subwavelength aluminum bilayer wire-grid. For this sample, a slight asymmetry of wire-grid can be seen resulting from the misalignment of the evaporation angle.

Download Full Size | PDF

Fig. 3.
Fig. 3. Measured transmission spectra and extinction ratio of an Al bilayer wire-grid with p=100 nm, h=94 nm, t=60 nm, and f=0.36.

Download Full Size | PDF

Fig. 4.
Fig. 4. The profiles of the of the electromagnetic field amplitudes (|E| and |H|) at λ=300 nm passing through an Al bilayer wire-grid with p=100 nm, h=94 nm, t=60 nm, f=0.36. The geometry of the simulation cell is shown in the right-most column. The refractive indices of aluminum, quartz, and PMMA are taken as n=0.276+3.61i, n=1.46 and n=1.48, respectively. The amplitudes are plotted with linear scale where the minima are set to zero and the maxima are set to maximum amplitudes of the individual field components.

Download Full Size | PDF

Fig. 5.
Fig. 5. Calculated transmission spectra and extinction ratio of an Al bilayer grating with p=100 nm, h=94 nm, t=60 nm, f=0.36. (a)The schematic diagrams of the cross-section models used in the calculations. The comparison of the TM transmission (b), TE transmission (c), and extinction ratio (d) for the two cross-section models and experiment.

Download Full Size | PDF

Fig. 6.
Fig. 6. Calculated transmission spectra and extinction ratio of an Al bilayer grating as a function of separation between the layers at the incident wavelengths of (a) λ=700 nm and (b) λ=300 nm. d=h-t, p=100 nm, t=90 nm, f=0.5. In this calculation the photoresist and the quartz substrate are omitted. The scattered data points are the results of the simulations of a bilayer wire-grid whereas solid lines are calculated by using Eq. (2) and the values listed in Table 1. In the insets TE transmission spectra are plotted with higher magnification.

Download Full Size | PDF

Fig. 7.
Fig. 7. Calculated transmission spectra and extinction ratio of the Al bilayer grating as a function of the lateral shift between the layers at the incident wavelengths of (a) λ=700 nm and (b) λ=300 nm. The definition of lateral shift is visualized in the inset. Note that Δx/p=0.5 corresponds to a bilayer grating as depicted in Fig.1. p =100 nm, t =90 nm, f=0.5.

Download Full Size | PDF

Tables (2)

Tables Icon

Table 1. The calculated transmittance (T0 ), reflectance (R0 ) and phase change upon reflectance (φ) of a single layer Al wire-grid at wavelengths of 700 and 300 nm for TM and TE polarization. p=100 nm, t =90 nm, f=0.5.

View Table | View all tables in this article
Tables Icon

Table 2. The comparison of the calculated performances of the single layer, bilayer and two Al wire-grids used in tandem. p=100 nm, t=90 nm, f=0.5. For the bilayer wire-grid the separation is d=20nm.

View Table | View all tables in this article

Equations (3)

Equations on this page are rendered with MathJax. Learn more.

T = ∣ E t ∣ 2 ∣ E i ∣ 2 ∙ n q ,
T = T 0 2 1 + R 0 2 − 2 R 0 cos ⁡ [ δ ] ,
δ = m 4 π d λ + 2 φ .
Select as filters
Select Topics Cancel
Top
       
© Copyright 2024 | Optica Publishing Group. All rights reserved, including rights for text and data mining and training of artificial technologies or similar technologies.
Privacy | Terms of Use